Condenser for a Refrigerator

ABSTRACT

According to an aspect of the present invention a condenser comprises an aluminum tube. The aluminum tube comprises a first interior surface in thermal communication with a first fluid and a second exterior surface in thermal communication with a second fluid. In an alternate embodiment a refrigerator comprises a condenser. The condenser further comprises an aluminum tube. The aluminum tube has a first interior surface in thermal communication with a first fluid and a second exterior surface in thermal communication with a second fluid. Wherein the first surface further comprises internal fins and the second surface further comprises external fins.

BACKGROUND OF THE INVENTION

This invention relates generally to heat exchangers for appliances, andmore particularly, to an aluminum heat exchanger for a refrigerator.

Known household appliances are available in various platforms havingdifferent structural features, operational features, and controls. Forexample, known refrigerator platforms include side-by-side single anddouble fresh food and freezer compartments, and vertically orientedfresh food and freezer compartments including top mounted freezercompartments, and bottom mounted freezer compartments.

As well known to those skilled in the art, various types ofrefrigerators are used to freeze or refrigerate foods. FIG. 1 is alongitudinal sectional view of a general refrigerator 100. Therefrigerator 100 comprises a housing 10 defined by an internal receivingspace divided into a freezing chamber 101 and a refrigerator chamber102, freezing and refrigerating chamber doors 12 and 13 respectively,are mounted to one side of the housing 10 for opening/closing thefreezing chamber 101 and refrigerating chamber 102. A number of devicesare used, including a compressor 20, a condenser 30, an expander (notshown) and an evaporator 40 for generating cold air in a cooling cycle.

Describing the operation of the refrigerator as set forth above, gaseousrefrigerant in a low temperature and pressure state is compressed into ahigh temperature and pressure by the compressor 20. The compressedgaseous refrigerant at high temperature and pressure is converted into ahigh pressure liquid as it is cooled and condensed while passing throughthe condenser 30. The high pressure liquid refrigerant experiences areduction in temperature and pressure while passing through the expander(not shown). Thus, the refrigerant is transformed into a low temperatureand pressure gas by absorbing heat from surrounding members as it passesthere through.

Then, air cooled by the evaporator 40 is circulated into the freezingchamber 101 primarily by operation of a fan 50 installed in anevaporator room 103. This circulation lowers the temperature of thefreezing chamber 101 and the refrigerating chamber 102.

The condenser 30 is generally used as a fin tube-type condensercomprising a refrigerant pipe 32 and a number of heat-radiating fins 34.The refrigerant pipe 32 is made of metal and continuously bent into amulti-layered, serpentine structure and configuration. Theheat-radiating fins 34 are arranged in a spaced parallel configuration.The fins are substantially perpendicular to pipe 32 and are attached tothe refrigerant pipe 32 via welding, and mounted in the shape of a thinpanel apparently crossing said bent refrigerant pipe 32.

It is the objective of the refrigeration industry world-wide to developsmaller, more energy-efficient heat exchangers in order to reducematerial and energy costs. Aluminum is preferred for its performance andmanufacturability. However, aluminum is susceptible to corrosion andtherefore does not meet life requirements for the condenser applicationin a household refrigerator.

SUMMARY OF THE INVENTION

According to an aspect of the present invention a condenser comprises analuminum tube. The aluminum tube comprises a first interior surface inthermal communication with a first fluid and a second exterior surfacein thermal communication with a second fluid.

In an alternate embodiment a refrigerator comprises a condenser. Thecondenser further comprises an aluminum tube. The aluminum tube has afirst interior surface in thermal communication with a first fluid and asecond exterior surface in thermal communication with a second fluid.Wherein the first surface further comprises internal fins and the secondsurface further comprises external fins.

In another alternate embodiment a refrigerator comprises a condenser.The condenser further comprises an aluminum tube. The aluminum tube hasa first interior surface in thermal communication with a first fluid anda second exterior surface in thermal communication with a second fluid.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view of a prior art refrigerator.

FIG. 2 is a perspective view of a condenser of the refrigerator of FIG.1 according to an aspect of the invention.

DETAILED DESCRIPTION OF THE INVENTION

It is contemplated that the teaching of the description set forth belowis applicable to all types of refrigeration units, including but notlimited to household refrigerators but include a standalonerefrigeration unit or may be connected to other appliances requiringheat exchange. The present invention is therefore not intended to belimited to any particular refrigeration device.

As indicated hereinabove, FIG. 1 illustrates a top mount refrigerator100 including a refrigerator chamber 102 and freezer chamber 101.Freezing chamber 101 and refrigerator chamber 102 are arranged in a topmount configuration where the freezing chamber 101 is above therefrigeration chamber 102. The refrigeration chamber is shown with door13. However, a more than one door may be used in a French doorconfiguration. Door 12 closes freezer compartment 101.

In accordance with known refrigerators, refrigerator 100 also includes amachinery compartment that at least partially contains components forexecuting a known vapor compression cycle for cooling air in thecompartments. The components include a compressor 20, a condenser 30, anexpansion device (not shown), and an evaporator 40 connected in seriesand charged with a refrigerant. The evaporator is a type of heatexchanger that transfers heat from air passing over the evaporator to arefrigerant flowing through the evaporator, thereby causing therefrigerant to vaporize. The cooled air is used to refrigerate one ormore refrigeration chamber or freezing chamber via fans 103.Collectively, the vapor compression cycle components in a refrigerationcircuit, associated fans, and associated compartments are referred toherein as a sealed system. The condenser 30 is traditionally constructedin a tube fin configuration from a ferrous metal. The construction ofthe sealed system is well known and therefore not described in detailherein, and the sealed system is operable to force cold air through therefrigerator 100.

The condenser 300 of the present invention is essentially a heatexchanger. The heat exchange is made up of heat exchanger tubes 301. Aheat exchanger tube 301 is used in a process that transfers heat betweena first fluid inside the heat exchanger tube 301 and a second fluidoutside of the heat exchanger tube 301. The efficiency of heat transferbetween the first fluid and the second fluid may be a complicatedfunction that depends on a number of variables such as thecharacteristics of the fluids, on the characteristics of the heatexchanger tube 301, and on the characteristics of fluid movementrelative to the heat exchanger tube 301. The term “fluid” refers to aliquid, a gas, or a combination of a liquid and a gas.

Aluminum is used in heat exchangers of scale where tube walls and finthickness can be such that oxidization of the aluminum does not resultin failure. Aluminum oxidizes by pitting. In thin walled aluminumstructures, used in household refrigeration, the pitting causes the heatexchanger to leak refrigerant.

FIG. 2 illustrates an exemplary condenser 300 in accordance with oneembodiment of the present invention. Condenser 300 is constructed fromaluminum providing improved heat transfer between the refrigerant andthe ambient air. The heat exchanger 300 comprises a flat tube 301 formedin a zig-zag or serpentine configuration made of aluminum. Corrugatedfins 302 made of aluminum are arranged between and joined to theadjacent straight tubular portions of the tube 301. A joint member 303also made of aluminum is joined to each end of the tube 301. Eachcorrugated fin 302 is joined to the tube 301 by fillets, which aresubstantially comprised of zinc.

The tube 301 and the fin 302 are each made of a material nobler than thefillet by at least 0.325 V in terms of potential. An example of a usefulmaterial which is nobler than the fillet by at least 0.325 V in terms ofpotential is an aluminum alloy comprising 0.1 to 1.0 wt. %, preferably0.2 to 0.5 wt. %, of copper, and the balance being aluminum andinevitable impurities. Also useful is an aluminum alloy comprising 0.1to 1.0 wt. %, preferably 0.2 to 0.5 wt. %, of copper, 0.1 to 1.0 wt. %,preferably 0.2 to 0.5 wt. %, of manganese, and the balance of aluminumand inevitable impurities. Also useful is an aluminum alloy comprising0.1 to 1.0 wt. %, preferably 0.2 to 0.5 wt. %, of copper, 0.1 to 1.0 wt.%, preferably 0.2 to 0.5 wt. %, of manganese, at least one of titanium,boron, chromium and zirconium in an amount of 0.01 to 0.1 wt. %, 0.01 to0.1 wt. %, 0.01 to 0.5 wt. % and 0.01 to 0.5 wt. % respectively, and thebalance of aluminum and inevitable impurities. It is especiallydesirable that the tube 301 and the fin 302 be made of a material noblerthan the fillet by at least 0.375 V in terms of potential. Although notlimitative, the tube 301 and the fin 302 are preferably made of the samematerial.

After the tube 301 and fin 302 are joined, the condenser 300 is coatedwith an anti-corrosion material. Non-limiting examples of anti-corrosivematerial include polyurethane, galvalume or mixed zinc/aluminum flakes.

The use of high performance aluminum with enhanced surface tubes in theheat exchangers of a refrigerator will contribute significantly inincreased energy efficiency as well as reduction in the size of thecondenser, and a corresponding reduction in the overall cost ofrefrigerant and related equipment.

While the invention has been described in terms of various specificembodiments, those skilled in the art will recognize that the inventioncan be practiced with modification within the spirit and scope of theclaims.

1. A condenser comprising: an aluminum tube comprising: a first surfacein thermal communication with a first fluid; and a second surface inthermal communication with a second fluid.
 2. The condenser according toclaim 1, wherein the first surface further comprises internal fins. 3.The condenser according to claim 1, wherein the second surface furthercomprises external fins.
 4. The condenser according to claim 2, whereinthe second surface further comprises external fins.
 5. The condenseraccording to claim 1, wherein the second surface further comprises anon-corrosive coating.
 6. A refrigerator comprising: a condenser,wherein the condenser comprises an aluminum tube, the aluminum tubefurther comprising: a first surface in thermal communication with afirst fluid; and a second surface in thermal communication with a secondfluid.
 7. The refrigerator according to claim 6, wherein the firstsurface further comprises internal fins.
 8. The refrigerator accordingto claim 6, wherein the second surface further comprises external fins.9. The condenser according to claim 7, wherein the second surfacefurther comprises external fins.
 10. The condenser according to claim 6,wherein the second surface further comprises a non-corrosive coating.11. A refrigerator comprising: a condenser, wherein the condensercomprises an aluminum tube, the aluminum tube further comprising: afirst interior surface in thermal communication with a first fluid; anda second exterior surface in thermal communication with a second fluid;wherein the first surface further comprises internal fins and the secondsurface further comprises external fins.
 12. The condenser according toclaim 11, wherein the second surface further comprises a non-corrosivecoating.